With approximately 50 percent of the U.S. dog population composed of mixed breeds, it's a question many dog lovers hear. In the past, guesses at the breed mix were based on appearance and temperament, but now DNA testing can unlock the mystery of a dog's genetic heritage.

With approximately 50 percent of the U.S. dog population composed of mixed breeds, it's a question many dog lovers hear. In the past, guesses at the breed mix were based on appearance and temperament, but now DNA testing can unlock the mystery of a dog's genetic heritage.

While parents spend about $600 a year per child in back-to-school purchases, pet parents will find it far less expensive to outfit their pooch for training classes or doggie day care. But as with any kind of shopping, it pays to research and compare before making your purchasing decisions.

While parents spend about $600 a year per child in back-to-school purchases, pet parents will find it far less expensive to outfit their pooch for training classes or doggie day care. But as with any kind of shopping, it pays to research and compare before making your purchasing decisions.

Reading assistance dog programs are popping up at libraries, schools and nonprofit organizations. Both organizers and participants say the literacy dogs are making a significant difference in the lives of children.

Reading assistance dog programs are popping up at libraries, schools and nonprofit organizations. Both organizers and participants say the literacy dogs are making a significant difference in the lives of children.

Since your dog hasn't mastered speaking in words yet, you may wonder how you can tell if your dog is feeling okay. It turns out, many of the clues can come from just looking at your dog and reading his body language.

Dr. Louise Murray, vice president of the ASPCA's Bergh Memorial Animal Hospital, shares some of the signs to be on the lookout for when it comes to your furry friend's health:

The above signs are just the beginning of being able to tell if your dog is healthy, though. Different parts of your dog's body hold the key to determining if she is truly healthy.

The MouthIf you notice that your dog has bad breath, it can be an indication of the need for a dental check up, or even something more. " Some odors may be indicative of fairly serious chronic problems," said Dr. Murray. "Liver or intestinal diseases may cause foul breath, whereas a sweet, fruity smells may be indicative of diabetes. If your dog's breath smells like ammonia or urine, kidney disease is a possibility. Any time you notice your pet has bad breath accompanied by other signs of ill health, schedule a visit to the veterinarian."

Another unlikely place to look to tell if your dog is healthy are his gums. "Once a week, with your dog facing you, lift his lips and examine his gums and teeth," says Dr. Murray. "The gums should be pink, not white or red, and should show no signs of swelling. His teeth should be clean, without any brownish tartar."

Not only can irregularities mean a problem with your dog's mouth, but it can also be a sign of gastrointestinal issues.

The EyesYour dog's eyes are also indicators of his overall health and wellbeing. In fact, many vets recommend that you give your dog regular home eye exams to keep you aware of any potential health problems. Dr. Murray explains how easy it is to do this: "Face your dog in a brightly lit area, and look into his eyes. They should be clear and bright, and the area around the eyeball should be white. His pupils should be equal in size, and there shouldn't be tearing, discharge or any crust in the corners of his eyes. With your thumb, gently roll down your dog's lower eyelid and look at the lining. It should be pink, not red or white."

If you do notice a problem, call your veterinarian. They can prescribe medicine to heal any eye disorders that can be impairing your pooch's vision.

The SkinBe mindful of your dog's skin, as well. "Your dog's skin is an indication of her overall health," says Dr. Murray. "When a skin problem occurs, your dog may respond with excessive scratching, chewing and/or licking. A wide range of causes -- including external parasites, infections, allergies, metabolic problems and stress, or a combination of these -- may be affecting your dog's skin."

Skin problems can also affect your dog's fur, which can result in excessive shedding.

Other more common signs of an ill or injured dog include pale gums, rapid breathing, weak or rapid pulse, change in body temperature, and difficulty standing. And of course, if you're ever really in doubt as to whether or not your pup is sick, making a trip to the vet can help, if only to alleviate your worry.

Stacey Brecheris a freelance writer. She has contributed to Animal Fair magazine, and her blogs have previously appeared on The Dog Daily.

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